Human beings cannot survive without the sun. All forms of energy we use ultimately come from solar energy. The photosynthesis that plants carry out each day also depends on the sun.
Solar energy is inexhaustible, clean and pollution-free. If more solar energy can be used directly, energy savings will be achieved.
Solar water heaters use solar energy to provide hot water. When the water heater is filled with water, it can reach the set water temperature under the irradiation of the sun. The advantage of solar water heaters is energy saving. , but the disadvantage is that in winter or on cloudy days, the electric auxiliary heating must be activated.
Solar cells are manufactured based on the photoelectric effect. When light shines on a metal plate, electrons from the metal plate escape and powerntent the entire circuit. Satellites in orbit will be equipped with solar cell panels. , but due to the low conversion rate of solar cells, they have not been used on a large scale.
Some hats worn in summer are equipped with a small electric fan. This small electric fan runs on solar energy. Some people wear watches that also rely on light to supplement the energy needed to run the watch.